Two-hand control for servomotors



Aug?- 28, 1945- w. F. GAYRING TWO HAND CONTROL FOR SERVO MOTORS Filed May 11, 1944 INVENTOR.-

WALLACE F. GAYRING ATTORNEYS.

Patented Aug. 28, i945 UNITED STATI-:sN 'PATENT OFFICE (Cl. 121-38) e 7 Claims- This invention relates to two hand controls for pressure fluid, as pnuematic, motors for operating machines, as for instance, machines having an opening and closing movement, as garment and laundry presses, and. particularly two hand controls, and has for its object a control wherein the fluid, as air, in passing through one control valve, when the valve is operated by its manual, operates means for locking the other valve, if it is not operated, so that both manuals must be operated substantially in unison and hence both hands of the operator must -be employed while the machine, as a press, is closing.

More speciiically, the invention has for its b- .iect a control including a pair of self-returnable manually operable valves of the combined intake and exhaust type normally arranged with the intakes closed and the exhausts open, these valves controlling the iiow of motive -fluid to a servomotor, as the cylinder of a, cylinder and piston motor, and means operated by the ilow of motive uid or air through either valve when that valve onlyiis operated for locking the other valve from operation, or locking the other valve from operation by blocking the operation of its manual.

`The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawing, which is a diagrammatic view showing this control.

In the control system here illustrated, the flow of motive fluid, as compressed air, to the servo'- motor is indirectly controlled by manual valves and directly controlled by a master valve, and the master valve controlled by the manual valves.

I designates the cylinder, 2 the piston, the cylinder being suitably mounted on the frame of the machine served by the motor, and the piston rod 3 being connected through suitable motion trans- Imitting means, a portion of which is shown at 4, to the movable parts of the machine, as the movable press head of a laundry and garment pressing machine.

5 designates the master valve for controlling the flow of motive iiuid from a feed line to the cylinder I. The master valve may be of any suitable form, size and construction, as for instance,

that shown in Davis Patent No. 2,341,696, issued February 15, 1944. It may, however, be omitted,

and the ow of air to the motor controlled by a pair of manually operable control valves.

6 and I designate respectively a pair of control valves of the combined intake and exhaust type. These valves may be of any suitable construction.

They are here shown as each including a casing having a sliding valve member therein formed with an intake head 8 and an exhaust head 9, coacting with suitable seats, with the intake head 8 closed and the exhaust head open. The valve member is self-returnable from operated to its normal position, as by a suitable spring I0. The intake ends of the valve casings are connected by conduits II and I2 in multiple with a master feed line I3A for motive fluid, as compressed air. A

The valve casings of the valves 6, 1 have exhaust passages I4 and I5 respectively controlled by the exhaust valve heads 9. In this embodiment of the invention, the valve casings 6 and 'I are connected in multiple, :by conduits It and I1 to the master valve 5 instead of to the cylinder of the motor, through ya conduit I8 common to both of them, the conduits I6, I1 opening into the valve the air exhausing through the exhaust port I4 or I5, saidmovable-members having portions movports 23, 24 and having shoulders or teeth 38, 39

casings of valves 6, 1 between the intake and exhaust valve heads.

I9 and 20 designate the manuals for the movstem 29 or 30 of the movable member or the control valve 6 or 1. Thus, when the manuals are operated in unison, their intake valve heads 3 will be opened and the exhaust valve heads 3 closed, and air will pass from the main line through the valve 6, conduits It and I8 to the master valve, and also from the mainline i3 through the valve 1 and conduits I1, I8 to 'the master valve, operating the last valve to permit air to iiow from the feed line 3I to the cylinder I to actuate the piston therein.

The means operated by the air passing through either valve 6 to prevent operation of the other valve, when the latter is not operated, as here shown, comprises movable members 32, 33 for thl'e valves 6, 1 respectively, Each of these members has a vane 34 or 35 arranged in the path of able into position to block the operation of each manual I9 or 20, when th'e other only is operated.`

The movable members 32, 33 are here shown as levers pivoted at 36, 31 respectively to the suprespectively, normally out of the path of complemental shoulders 4I), 4I on the manuals I9 and 20 respectively, when the lever 32 or 33 is operated by the current of air passing through the exhaust I4 or I5. The levers 32, 33 are here shown as does not have time to pass in an appreciable amount through the exhaust passages Il, I5 at least with force suicient to operate the vanes 34, 35. With th'e control valves 6, I vso operated, the air passes from the valve 6 through the conduits I3, I8 to the master motor 5 and from the valve casing 1 through the conduits I1, I8 to the mast/r valve and from the master valve to the cylinder I and means operated by the current of exhausting iluid from either of the control valves when the other control valve only is operated, to prevent the unoperated valve from operation.

2. A.two hand control including a pair of selfreturnable control valves of the combined intake and exhaust type normally arranged" with their intakes closed and their exhausts open and connected independently 1n a power fluid feed line, so that power iluidjn passing through either valve when either only is operated passes out through the exhaust of the other valve, a pair of manuals for operating the valves respectively, manuals for operating the valves, and means operated by the current of exhausting fluid from either of the control valves when the other control valve only is operated to lock the manual for the unoperated of th'e servomotor. When, however, but one manual is operated, as for instance, the manual to open the intake of the control valve 6 and close the exhaust thereof, air passes from the main linev I3 through the conduit I, valve casing B, conduit I6 through conduit l1, casing of the valve 'I and out through the exhaust I 5 of the casing of the valve 1, as this valve has not been operated. The current of exhaust air through the exhaust port I5 strikes the vane 35 and actuates the lever 33 to move its teeth 39 into interlocking engagement with the teeth 4I of the manual 20, thus blocking operation of the manual. The same operation takes place to block the operation of the manual I9 by operating the lever 32, when the manual 20 is operated and the manual I9 not operated. Thus, a particularly simple and eilicient means is provided without the use of mechanical interlocks to lock` one manual or its valve from operation, when the other manual only is operated, and thereby compelling both manuals to be operated simultaneously to effect the energization of the power cylinder I.

The pivots 36, 3l for the levers 32, 33 are of any suitable antifriction type, as cone bearings.

The manuals are naturally and quickly operated by the operator and are usually held operated until the press closes or is in a safe position. Of course, this object may be defeated if the operatr purposely plays with the manuals by depressing them so slowly that the air passing through thevalve casing B, 1, passes out predominately through the exhaust passages I4, I5, actuates the varies 34, 35 and locks both manuals I9, 20 before they were fully depressed. This operation, however, prevents either exhaust valve from closingfully and therefore no air will build up in the master valve 5 and the machine will not operate. Slow operation of both manuals 25, 26 causes both to be locked from full operation.

A. release valve R is provided to release the air from the master valve 5 after the cylinder I has completed its operation, This release is accomplish'ed through pipe 50 and out exhaust port 5l of release valve R.

What I claim is:

1. A two hand control including a pair of selfreturnable control valves of the combined intake and exhaust type normally arranged with their intakes closed and their exhausts-open and connected independently in a power fluid feed line. so

, that power iiuid in passing through either valve when either only is operated passes out through the exhaust of the other unoperated valve,' a pair ci' manuals for operating the valves respectively,

valve from being operated.

' 3. A two hand control including a pair of sel!- returnable control valves of the combinedintake and exhaust type normally arranged with their .intakes closed and their 'exhausts open and connected independently in a. power uid feed line, so that power fluid in passing through either valve when either only is operated passes out through the exhaust of the other valve, a pair of manuals for'operating the valves respectively, manuals for operating the valves, and means operated by the current of exhaustingfluid from either of the control valves when the other control valve only is operated to prevent the'unoperated valve from operation, said means including a movable locking member, one for each valve, each having a vane located in the path of the exhaust from the com: panion control valve.

4. A two hand control including a pair of selfreturnable control valves of the combined intake and exhaust type normally arranged with their intakes closed and their exhausts open and connected independently in a power fluid feed line, so that power uid in passing through either valve when either only is operated passes out through the exhaust of the other valve, a pair of manuals for operating the valves respectively, manuals for operating the valves, and means operated by the current of exhausting fluid from either of the control yalves when the other control valve only is operated to lock the manual for the unoperated valve from being operated, said means including movable locking members, one for each control valve, each member having a vane located in the path of the exhaust of the companion control member and a portion movable in the path of the companion manual to block when operated by the exhausting air current said companion manual from operation.

5. A two hand control including a pair of selfreturnable control valves of the-combined intake and exhaust type normally arranged with their intakes closed and their exhausts open and connected independently in a. power fluid feed line, so that power fluid in passing through either valve when either only is operated passes out through the exhaust of the other valve, a pair of manuals for operating the valves respectively, manuals for operating the valves, and means operated by the current of exhausting fluid from either of the control valves when the other control valve only is operated to lock the manual for the unoperated valve from being operated, ssaid means including a self-returnable lever for each control valve having a yvane located in the path of the exhausting duid from the companion valve, so that the lever is moved on its pivot by the exhausting air, the lever having a portion movable into the path a valve, conduits connecting the valves in multiple to the master valve and arranged so that said conduits are normally open to exhaust through the control valves and hence one only open to exhaust when the other valve only is operated, and means operated by the current of exhausting fluid from either of the manually operated valves, when only one is operated, to lock the other unoperated valve from operation.

7. A control for servo motors including a master valve, a pair of self-returnable control valves of the combined intake and vexhaust type normally arranged with their intakes closed and exhausts open, and connected independently of each other in a power iiuid feed line, for controlling the iiow of motive iiuid to the master valve, which control valves must be operated in unison to effeet the flow of fluid to the master valve, a pair of manuals for operating the valves, one for each valve, conduits connecting the valves in multiple to the master valve andv arranged so that said conduits are normally open to exhaust through the controlvalves and hence one only open to exhaust when the other. valve only is operated, and means operated by the current oi exhausting iluid from either of the manually operated valves, when only one is operated, to lock the other unoperated valve from operation, the last means coacting directly with the manual means to lock the manual means from operation.

WAILACE F. GAYRING. 

